1. Concept Summary Batesville High School Physics
Impulse & Momentum
Concept Summary
Batesville High School Physics

2. Momentum
Momentum is what Newton called the “quantity of motion” of an object.

3. Momentum The momentum of an object: Depends on the object’s mass.
Momentum is directly proportional to mass.
Depends on the object’s velocity.
Momentum is directly proportional to velocity.

4. Momentum
In symbols:
p = mv p m v

5. Momentum Momentum is a vector quantity.
Common units of momentum: kg m/s

6. Impulse The impulse exerted on an object depends on:
The force acting on the object.
Impulse is directly proportional to force.
The time that the force acts.
Impulse is directly proportional to time.

7. Impulse
In symbols:
I = Ft I F t

8. Impulse
Impulse is a vector quantity.
Common units of impulse: N s

9. Impulse & Momentum
The impulse exerted on an object equals the object’s change in momentum.

10. Impulse & Momentum
In symbols:
I = Dp

11. Conservation of Momentum
Since impulse = change in momentum, If no impulse is exerted on an object, the momentum of the object will not change.

12. Conservation of Momentum
If no external forces act on a system, the total momentum of the system will not change.
Such a system is called an “isolated system”.

13. Conservation of Momentum
Momentum is conserved in every isolated system.

14. Conservation of Momentum
Another way to think about it is:
Internal forces can never change the total momentum of a system.

15. Conservation of Momentum
In practice, for any event in an isolated system:
Momentumafter = Momentumbefore

16. The End.